Sandstone (Quartz-rich)
Arenite (SiO2)
Category
Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.
Sandstone (Quartz-rich)
Arenite (SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Yellow Jasper
Cryptocrystalline Quartz (SiO2) with iron inclusions
Chert (variations include Chalcedony and Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (containing fossil leaf impression)
Microcrystalline silicon dioxide (SiO2)
Orange Calcite (likely polished specimen)
Calcite
Zebra Jasper
Silicon Dioxide (SiO2) - Macro-crystalline Quartz/Chert with impurities
Jasper (specifically Red Jasper)
Silicon Dioxide with Iron Oxides (SiO2 + Fe2O3)
Amethyst (Agate/Chalcedony variety)
Silicon Dioxide (SiO2) with iron impurities
Yellow Jasper
Silicon Dioxide (SiO2) with high iron inclusion
Petrified Wood
Silicified Wood (SiO2)
Chert (containing Iron Oxide spots)
Microcrystalline Quartz (SiO2)
Amethyst with Marcasite accents
Amethyst (Silicon Dioxide SiO2) and Marcasite (Iron Sulfide FeS2)
Hag Stone
Perforated Sedimentary Rock
Shale or Siltstone
Sedimentary Rock (Siliciclastic)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Fossiliferous Chert (Chert with Crinoid Stem Impression)
Chert (SiO2) with fossil Anthozoan or Crinoid columnals
Petrified Wood
Silicified wood (Quartz, Chalcedony, or Opal)
Calcite with iron staining
Calcium Carbonate (CaCO3)
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Silty Shale
Silty Shale (Fissile Sedimentary Rock)
Shale (Ferruginous)
Laminated Mudrock (Siliciclastic Sedimentary Rock)
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
Quartz (Milky Variant)
Quartz (Silicon Dioxide, SiO2)
Sandstone (with Iron Staining)
Clastic sedimentary rock (SiO2 with Fe2O3 oxides)
Sandstone
Arenite (primarily SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite (primarily SiO2)
Chert (v. Flint)
Sedimentary Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite
Green Aventurine (likely)
Silicon dioxide (SiO2) with fuchsitemica inclusions
Garnet Schist
Garnetiferous Micaceous Schist
Porphyritic Basalt (Peanut Obsidian/Star Galaxy-style)
Porphyritic Basalt (Silica-rich Volcanic Rock)
Quartz Crystal Cluster
Quartz (Silicon Dioxide, SiO2)
Quartz (Milk/Citrine variety)
Silicon Dioxide (SiO2)
Chert (Jasper nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Crinoid and Coral Fossils in Limestone
Fossiliferous Limestone with Rugosa (order) and Crinoidea (class)
Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
River Rock (likely Quartzite or Quartz-rich Siltstone)
Quartzite (SiO2)
Conglomerate
Polymictic Conglomerate
Granite Pebble
Intrusive Felsic Igneous Rock (primarily SiO2 with Al2O3, K2O, Na2O)